Carlos P. Long, of Procter & Gamble Co., president ofAmerican Oil Chemists9 Society, and John J. Voilertsen, of the
'Armour Laboratories, treasurer of AOCS; V. F. Abel, A. G. Parker, and Francis B. White, all of Foster Wheeler Corp.
Soap vs. Detergents Issue Debated by Oil Chemists A STAFF REPORT
THE American Oil Chemists' Society interrupted a 10-year absence from New York when they held their twenty-second annual fall meeting in that city's Hote. Pennsylvania, Nov. 15 to 17. A registration of over 750 members attended the conclave to hear a total of 60 papers on all phases of fat and oil chemistry and inspect the 45 displays that constituted the exhibit running concurrently with the technical sessions of the program. The success of this return to New York prompted several spokesmen for the society to predict that serious consideration would be given to the scheduling of future meetings in the eastern metropolis. Soap and
Detergents
The soap and detergent part of the technical sessions of the meeting opened with a paper by C. S. Miner, Jr., and C. M. Weil of the Glycerine Producers Association in which the application of spectrophotometry methods to the determination of glycerol color was discussed. The authors pointed out that the conventional method of color determination in this field has been the Lovibond system, which has all of the disadvantages of visual methods of analysis. For this reason the study by the authors of the feasibility of spectrophotometry determinations was initiated. Because of the prevailing practice of reporting glycerol color in Lovibond units, however, it was necessary that the investigation also develop a method whereby the results of the spectrophotometry measurements could be translated into Lovibond units. Wave lengths suitable for such translation were found to be 440 m/u for Lovibond yellow and 520 m/* for Lovibond red. The mathematical relationships between the optical density and 3556
Lovibond color were determined for 55 samples of glycerol. The results were found to be linear for both the yellow and the red. Additional work on the suitability of the spectrophotometric type of determination as a means of measuring glycerol color showed that good agreement could be expected between these methods and the visual. It was also found that the values obtained from the spectrophotometer are at least as reliable as those obtained in the older method. A continuous process for the manufacture of soap was described in the paper by L. D. Jones and L. Sender of the Sharpies Corp. In general, the new process operates on the chemical principles of the full boil kettle process and uses fats, oils, and caustic as raw materials and delivers neat soap and spent lye. It differs from the older method in that it is mechanized to use centrifugal force instead of gravity to make all of its separations. The water and the reagents flow through the process countercurrently to the flow of fat, oils, and soap. The continuous flow through the process is divided into a number of stages. Each of these consists of an element where the fat and reagent are mechanically mixed and another in which a centrifugal separation of the reacted phases takes place. These stages correspond to the "changes" of the kettle process. The authors claimed that the combination of three saponification and washing stages along with one fitting stage equals the performance of the best kettle practice in the completeness of saponification, glycerol recovery, and the control of caustic and salt in the neat soap product. It was also declared that these results are obtainable because of the completeness of
CHEMICAL
separation brought ab»out by the use of centrifugal force. The additional benefit pointed out in the conclusion of the paper was that the retention time of fat and soap in process is less than two hours resulting in less degradation in color. Foster D. Snel! of Foster D. Snell, Inc., and chairman of this meeting of the AOCS, delivered a paper on time problem of growing concern, "Soap Versus Detergents." Dr. Snell drew attention to the considerable growth of the detergent industry in the relatively few years of its life as compared with that of the soap industry. The speaker pointed out that perhaps the principal virtue of tbe detergent is its ability to work in hard water. It has teen estimated, he continued, that over half of the soap used in household applications is employed to soften hard water in order to make additional soap effective This is a particularly interesting contrast because it has been observed that the detergents usually work better in hard than soft water, none being wasted in the task of water softening. The world-wide fat shortage has contributed greatly to ttoe increased use of detergents, Dr. Snell declared. Currently a pound of detergent is sold for every five pounds of soap. The largest manufacture of synthetic detergents is concerned with the production of sodium alkyl aryl sulfonates which are of petroleum origin. Other a.nion-active agents being produced on a large scale were listed by the speaker as alkyl sulfates and sulfated monoglycerides. both derived from fats and oils by processes more costly than those used in thé manufacture of soap. A different type of detergent, mentioned by Dr. Snell, is the nonionic type produced by the addition of ethylene oxide to long chain alcohols, naercaptans, phenols, and
AND ENGINEERING
NEWS
acids. This type, he said, is well repre sented on the market, but those used most widely do not come from fat stocks. The importance of glyceridic oils in our national economy was emphasized in the paper by P. H. Groggins of the U. S. Department of Agriculture in his paper on the subject. The author pointed out that the well being of the population, the national defense, and the industrial econ omy all are dependent upon the supply of both edible and industrial glyceridic oils. The dollar value of oils and fats is subject to wide fluctuation, the speaker declared, but in general it will be found to constitute about 10% of the value of all farm crops. The speaker predicted that the food market for oils in the foreseeable future will be good. This forecast is based, he claimed, on reported population trends and the improvement in the American nutritional standard of living. It is also likely, he continued, that the future will bring shifts in the consumptions of particular oils because of the change in buying habits of a large portion of the population. For this reason, the speaker said, research directed toward the im provement of the eating and keeping qualities of the edible seed oils will be a major requirement in the near future. In spite of the twofold increase in the domestic production of industrial oils in the past 20 years, the speaker revealed that it was necessary for this country to import about 50% of its requirements in this field for the year 1947. Due to the fact that this * part of the natural oil business is facing ever-increasing com petition from products made from nonagricultural sources it will be necessary for glyceridic oil chemists to intensify their research efforts. This activity must also be combined with more efficient farm management and a "hopeful and helpful economic environment, " the speaker concluded. Analytical Metfiods A new method for the analysis oi aethyl ester fractions was described in the paper by H. A. Schuette and Stephan X>al
Nogare of the University of Wisconsin. The method of the authors involves the conversion of the* unsaturated com ponents of the fractions obtained in the analytical distillation of fatty oil methyl ester to short chain acidic fragments by permanganate oxidation. The subsequent adsorption of these materials on alumina tinted with bromothymol blue is the basis for the determination. Recovery experiments showed that the removal of these fragments from the alumina is practically quantitative pro vided that acids lower than lauric are not present in appreciable amounts. The paper reported that duplicate samples agree withii* 1% of the saturated ester content and that the reproducibility of the results is of the order of 0.6%. It was also found that in a series of deter minations run by this method, the results obtained were in good agreement with those achieved by calculation from iodine and thiocyanogen numbers or by alkali isornerization. The methods of drawing representative samples from loaded tank cars at destina tion, particularly those concerned with crude vegetable oil sampling, were re viewed in the paper by Egbert Freyer of Spencer Kellogg and Sons. The author pointed out the difficulties inherent in the present methods particularly where settlings are present. He claimed that data obtained by these methods often lead to a downgrading of the oil because of the inclusion of a disproportionate share of bottoms in the sample. A new method was proposed by the author in which two selective samples are taken, one from the foots stratum in the car and another from the main body of oil excluding the foots stratum. The first of these is smaller than the second. By means of a prepared reference table showing the relative amounts of oil embodied in each of the strata sampled as compared to the total car volume, a representative sample of the oil may be put together from the independent sam plings. If the bottom stratum is large and not of uniform composition, the method can be
/ . S. Stokes, W. F. H. Schults Coy.; F. C. Low, Du Pont Co,; and J. R. Harrison, Rath Packing Co.
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modified to take a weighted composite sample from various depths within the foots layer, the author explained. The uutrition session of the program included a paper by Ε. Η. Stotz of the University of Rochester in which the biological synthesis of fatty acids was discussed. Dr. Stotz pointed out that the theories offered for the mechanism of the conversion of carbohydrate to fat in both plants and animals have been poorly substantiated by experiment- He said that although the direct condensation of 6-carbon substances to fatty acids has been suggested, it has been more generally held that the conversion takes place through the successive condensation of the 2-carbon fragments of carbohydrate metabolism. This seems to explain better the natural occurrence of fatty acids containing even numbers of carbon atoms. This theory was also given support by the use of isotopic tracers. It was found that the isotopic carbon of injected acetic acid is incorporated in the syn thesized fat, apparently by successive condensation of the 2-carbon unit· The present concept of energy rich phosphorus compounds and their role in biological syntheses has suggested the possibility that perhaps a 2-carbon energy-rich phosphate compound like acetylphosphate is the immediate condensing agent. The flavor problem of soybean oil was the topic of the paper by H. J. Dutton, A. W. Schwab, H. A. Moser, and J. C. Cowan of the Northern Regional Research Laboratory. The authors revealed the successful use of citric acid and sorbitol on a commercial scale to improve the initial quality of soybean oil and increase its oxidative and flavor stability during storage. They declared that it is not necessary to use heat to activate the citric acid. It is helpful, they said, to add the citric acid at the beginning of the deodorization process to achieve protection of the material during this treatment. Phosphatides added to the deodorizer also increase the oxidative and flavor stability of soybean oil and serve to counteract the pro-oxidant effect of added iron.
H. W. Vahlteich, Best Foods, Inc., vice chairman of the meeting, and Alton Sawyer, Lever Bros. Co.
1948
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